1. Field of the Invention
The present invention relates to a small-arm in which a locking mechanism of a revolving barrel and a trigger mechanism enabling shooting in a double-shot burst is solved.
2. Description of the Prior Art
The small-arms, above all pistols using an efficient ammunition must have during shooting a barrel firmly locked with a bolt element so as to prevent a premature opening of a bolt element during a shot and cracking of a cartridge case. Known are several constructions of locking mechanisms.
The most known and used mechanism is a so-called Browning system, with a barrel having slots on its upper surface, in which engage protrusions of the inner surface of a bolt element shell. At the moment of a shot, the bolt element with a barrel is thrown backwards by force of a recoil, whereby a barrel in its rear part slopes downwards because it is hingedly firmly connected with a pistol frame.
Another known mechanism is using for the pistol mechanism locking various special parts above all pivoted bars or vertically sliding wedges which after a short movement of movable parts backwards change their position as a result of an interaction with the firm frame of a pistol, thus releasing the locking mechanism. These constructions do not guarantee the high accuracy of shooting and the complexity of their mechanisms forms preconditions for the failure rate and the production thereof is time-consuming.
Another known mechanism is using for locking and unlocking a rotary construction of a barrel having two surface protrusions one of which is sliding inside an inclined groove of a frame and the second one is sliding inside a transverse groove of a bolt element. At the moment of a shot, a protrusion located in a transverse groove ensures a reliable connection causing that both a bolt element and a barrel are carried by the recoil. The movement of a barrel backwards is accompanied also with its rotation round a longitudinal axis, because the second protrusion of a barrel is sliding in an inclined groove of a frame. After a slight revolving of a barrel by a certain angle, the locking protrusion will leave a transverse groove of a bolt element enabling the release thereof.
Although this mechanism guarantees higher accuracy of shooting in comparison to the constructions mentioned above, highly exacting character of production and complexity of parts are the main drawbacks and therefore it is only seldom utilized in the practice.
To fire a shot off it is necessary to ignite a cartridge cap whereto serve various trigger mechanisms for the purpose of shooting in bursts combined with various burst length limiters.
Out of the mechanical limiters the most known are so-called ratchet- or ridge-like limiters, called after the shape of a part on which a number of teeth is formed, identical to the number of shots carried out in a given burst.
All these up to the present known mechanisms, intended for shooting in many modes contain a great deal of small parts and their interconnections, resulting in their considerable failure rate being the main drawback of these mechanisms.
After firing all the cartridges from a cartridge magazine off, its feeder will push a locking catch down and this will catch a bolt element in the locking position onto bearing surfaces. An operator will change a cartridge magazine for a new one and releases the locking catch with his finger. The known double-sided locking catches are constructed above all as the shafts with one welded controllable safety lever whereby the opposed controllable safety lever is slid on a groove and secured against disengagement by a flexible wire.
The drawback of this construction is in its complexity and an exacting character of the production.
The task of this invention is to provide a weapon of a simple construction containing lesser amount of parts that are easier to produce, enable using of an effective ammunition and setting more shooting modes and providing simple service and also shooting.
The drawbacks mentioned above are to a large extent removed and the mentioned task solved by a firearm having a revolving barrel, enabling shooting with a double-shot burst, consisting above all of a mechanically interconnected frame, a barrel, a breech mechanism and a trigger mechanism according to this invention, the subject matter of which consists in that after a shot, by force of a recoil, the barrel is slightly revolved as well due to a slip of its recess over a frame pin and thereafter an unlocking recess will slide under the locking protrusions of the bolt element thus unlocking itself from the barrel.
Accordingly, after a round, a hammer catch is transmitted to an additional double-shot draw bar causing a striking hammer to start a mechanism of a second round firing after which the hammer catch is returned to the starting position catching the striking hammer.
In a bed of the barrel of the front upper part of the frame, there is a crosswise placed pin enabling sliding and slight revolving of the rotary formed barrel having on its rear thicker bottom part a recess shaped in a helical form and an unlocking recess formed from above or from aside.
A single-shot groove laterally formed on the inner part of the bolt element has a functional surface situated closer to the front part of a weapon and on the opposed side of the bolt element there is formed a double-shot groove, the functional surface of which is situated closer to the rear part of a weapon. On this opposed side also situated is an additional double-shot draw bar disconnectable via a safety catch situated in a frame.
In a hole of the rear part of the frame there is a locking catch placed pivotably by means of its rim, consisting of a formed pressed piece made of steel metal.
In the firearm constructed in this way it is possible to set many functions as for example securing, firing of individual rounds, shooting with a limited burst. In the firearm according to this solution, the barrel is firmly locked with the bolt element thanks to the rotation of the barrel round its longitudinal axis, whereby its rotation is activated by a revolving notch of a helical form. At a shifting motion backward through this helical surface, the barrel slides over a pin inserted in the frame of a weapon causing its revolving.